This invention relates generally to steam turbine preservatives, and more particularly to a novel steam turbine preservative and method of preserving steam turbine components utilizing an amine polymer.
Steam turbine components have traditionally been preserved with one of two principal preservatives: either petroleum derivatives such as oils and greases or hard coatings such as lacquers. On the one hand, lacquers tend to crack over time thereby losing their efficiency as a preservative. Petroleum derivatives, on the other hand, tend to "heal" cracks and scratches in the film surfaces of the preservative, thereby maintaining their efficiency as a preservative in spite of such temporary cracks and scratches. However, preservatives comprised of petroleum derivatives must be thoroughly removed from the steam turbine component to which they are applied, prior to the installation of such components, since substantial concentrations of oils and greases containing impurities such as sulfur and heavy metals must be necessarily avoided in feedwater supplies for the steam generators and turbines. This is especially the case in nuclear power plants where there is a concern for steam generator corrosion due to the presence of such impurities. Moreover, it is undesirable to assemble the turbine without preservatives since it may sit for extended periods of time before being operated. In the humid atmosphere to which such turbines may be exposed, corrosion will readily occur.
While preservatives for steam turbine components comprised of petroleum derivatives do offer the advantage of their quick removal from the component to which they are applied, their lacquer coating counterparts are difficult to remove and do not "heal" cracks and scratches formed in their surfaces. Moreover, lacquer coating preservatives if left on the component have a tendency of being caught on conventional condensate polisher resins as particulate matter when such polishers are employed in the condensate subsystem. It would, therefore, be desirable to provide a steam turbine preservative and method of preserving steam turbine components which would not suffer from the above described disadvantages experienced in the utilization of preservatives comprised of petroleum derivatives or lacquer coatings.